There are a number of conventional ways to make multi-colored fabrics. Some of these ways utilize solution dyed or package dyed yarns (where the fiber is dyed during the polymerization process, or individually in yarn form, respectively.) The dyed yarns can then be selectively positioned during the fabric formation process (e.g. knitting or weaving process), to produce a patterned fabric. Examples of this type of construction are jacquard woven and jacquard knit fabrics.
Another way to create multi-colored products is to blend multiple types of fibers together before dyeing. The fibers are then exposed to one or more classes of dyes that affect only one of the fiber constituents, such that one fiber component is dyed a different color from the other. Such examples include common blends such as polyester/cotton and polyester/nylon fabrics.
Another common technique used is fabric printing. A fabric can be printed to apply more than one color to it, or it can be dyed an initial base shade, and then overprinted.
In each of these cases, multiple processes and raw materials must be used. In package and solution dyed yarns, the yarn is processed and then made into fabric. Because this can necessitate a large inventory of small quantities of different colors of yarns and because of the number of steps involved in the process, it is traditionally done at a much higher cost than dyeing a solid fabric. For blends, the dye mix must consist of multiple sets of dyes for each yarn and compatible chemistry so that the fibers may be dyed together in the same bath. When printing, another step is added after dyeing for the overprint pattern, and in the case of screen printing, a different screen must be manufactured for each design required. All of these processes add increased cost, labor, and time to the creation of the final product.
An additional method for achieving multi-colored fabrics is described in commonly-assigned U.S. Published Patent Application Serial No. 20020124323A1 to Cliver et al. published Sep. 12, 2002, the disclosure of which is incorporated herein by reference. This application describes a process for providing a patterned resist chemistry across the fabric surface and then dyeing the fabric. The regions corresponding to the locations of the resist chemistry do not become saturated with the dye, and thus enable the achievement of multi-toned fabrics through a single dye formula. To achieve multi-colored fabrics, a dye can be included in the resist chemistry, so that the regions where it is applied are dyed a different color.
Another method that has been used to create tone-on-tone variations in fabrics is described in commonly-assigned U.S. Pat. Nos. 4,499,637 and 4,670,317 to Greenway, the disclosures of which are incorporated herein by reference. In this method, a fabric, either before or after dyeing, is contacted in a pattern with heated pressurized streams of fluid, to thermally modify (i.e. change the orientation of) fibers in certain regions. When the fabric is subsequently dyed, two-tone dye effects can be achieved. While providing many advantages, to date this method has been limited to the production of tone-on-tone effects as opposed to the production of fabrics of two or more different colors through a single dye formula.